Question

Prosze o rozwiaznia rownania: cos(2x + pi/3) = -1/2

Answer 1

cos(2x+π/3)= -1/2

                               2π-2π/3=4π/3

 

2x+π/3= 2π/3+2kπ  v 2x+π/3=4π/3+2kπ

2x=π/3+2kπ  v 2x= π+2kπ  /:2

x=π/6+kπ v x=π/2+kπ